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  <script>

    var foo1 = ""
    var foo2 = false

    // == 运算符,在类型不同的情况下,会将运算元先转成Number的值,再进行比较
    console.log(Number(foo1))
    console.log(Number(foo2))
    console.log(foo1 == foo2) 

    // === 运算符在类型不相同的情况下直接返回false
    console.log(foo1 === foo2);
    
    
  </script>
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